package com.sdgakj.utils;

import java.util.Collection;
import java.util.List;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaBuilder.In;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import org.apache.commons.lang3.StringUtils;
import org.springframework.data.jpa.domain.Specification;
import org.springside.modules.utils.Collections3;
import com.google.common.collect.Lists;

public class DutyAssignSpecifications {

	@SuppressWarnings({ "rawtypes", "unchecked", "incomplete-switch" })
	public static <T> Specification<T> bySearchFilter(final Collection<DutyAssignSearchFilter> filters, final Class<T> entityClazz) {
		return new Specification<T>() {
			@Override
			public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
				if (Collections3.isNotEmpty(filters)) {

					List<Predicate> predicates = Lists.newArrayList();
					for (DutyAssignSearchFilter filter : filters) {
						// nested path translate, 如Task的名为"user.name"的filedName, 转换为Task.user.name属性
						String[] names = StringUtils.split(filter.fieldName, ".");
						Path expression = root.get(names[0]);
						for (int i = 1; i < names.length; i++) {
							expression = expression.get(names[i]);
						}
						switch (filter.operator) {
						case EQ:
							predicates.add(builder.equal(expression, filter.value));
							break;
						case NOTEQ:
							predicates.add(builder.notEqual(expression, filter.value));
							break;
						case LIKE:
							predicates.add(builder.like(expression, "%" + filter.value + "%"));
							break;
						case GT:
							predicates.add(builder.greaterThan(expression, (Comparable) filter.value));
							break;
						case LT:
							predicates.add(builder.lessThan(expression, (Comparable) filter.value));
							break;
						case GTE:
							predicates.add(builder.greaterThanOrEqualTo(expression, (Comparable) filter.value));
							break;
						case LTE:
							predicates.add(builder.lessThanOrEqualTo(expression, (Comparable) filter.value));
							break;
						case BETWEEN:
							predicates.add(builder.between(expression, (Comparable)filter.value, (Comparable)filter.value2));
							break;
						case IN:
							In<Long> in = builder.in(expression);
							String[] strs = filter.value.toString().split(",");
							for (String str : strs) {
								in.value(Long.valueOf(str));
							} 
							predicates.add(in);
							break;
						}
					}
					// 将所有条件用 and 联合起来
					if (!predicates.isEmpty()) {
						return builder.and(predicates.toArray(new Predicate[predicates.size()]));
					}
				}
				return builder.conjunction();
			}
		};
	}
	
}
